Kneeling during the national anthem started in August 2016 when former 49ers quarterback Colin Kaepernick refused to stand for the "Star-Spangled Banner" as a means of protesting racial inequality and police brutality. Dozens other NFL players, as well as numerous other athletes across America, ultimately joined him. The protests grew during the 2017 season after Trump criticized NFL players who chose to follow suit. Trump said owners should "fire" NFL players who protest the anthem and referred to them as "son[s] of b------". Players responded by protesting en masse.

NFL owners voted on a new national anthem policy in May. But this was put on pause before the start of this season and no policy has been implemented. Some players have continued their protests against police brutality and racial inequality.

Kaepernick hasn't played an NFL game since the 2016 season but he became the face of Nike's 30th anniversary "Just Do It" campaign that began this fall.